Yes, a lever class can change depending on the position of the fulcrum and the effort and load applied to the lever. This change in class is known as the principle of moments.
The three types of lever classes are first class, second class, and third class. First class levers have the fulcrum placed between the effort and load, second class levers have the load between the fulcrum and effort, and third class levers have the effort between the fulcrum and load.
Yes, the length of a lever can affect its class. The longer the distance between the fulcrum and the point where the effort is applied, the greater the mechanical advantage of the lever.
The mechanical advantage of a lever can be determined by dividing the distance from the fulcrum to the effort by the distance from the fulcrum to the load. This ratio is also known as the ideal mechanical advantage.
No, the direction of force applied to a lever does not change its class. The class of a lever is determined by the position of the fulcrum and the effort and load, not the direction of force.